Much remains murky about the scandal dubbed Climategate, which involves the release last fall of e-mails leaked or stolen from the Climate Research Unit at the University of East Anglia. Initial accounts focused on e-mails that seemed to show scientists deliberately distorting research to make the danger of global warming appear worse than it is. Others have suggested this could be a misreading of the e-mails, most of which, though not all, simply suggest working professionals wrangling over contentious issues and occasionally slagging their critics.

The question of scientific misconduct is still under investigation at East Anglia. But what's clear is that the scandal - one of the biggest to hit the science community in the past decade - wouldn't still be hanging so heavily over climate-change researchers if it weren't for bloggers such as Stephen McIntyre.

A Toronto-based retired mining executive who has emerged as a uniquely polarizing figure in one of our era's most contentious issues, Mr. McIntyre has been an outspoken critic of the CRU's research on his blog, Climate Audit, and has launched countless freedom-of-information requests for data used by its scientists. He likes to speculate that the Climategate e-mails were released by a whistleblower unhappy at the research unit's intransigence over making data public. That may or may not be true, but whoever got hold of the e-mails and made them public clearly kept a close eye on Mr. McIntyre's struggles with the CRU, which form a strong theme in the leaked e-mails.

Many reveal researchers bristling at the armchair scientist's criticism. One e-mail, written by Benjamin Santer of the Lawrence Livermore National Laboratory in California, called Mr. McIntyre "the self-appointed Joe McCarthy of climate science." Another referred to him as a "bozo." But Mr. McIntyre doesn't mind the criticism: His website is now getting a million hits a month, double what it got before Climategate.

In the wake of the scandal, blogs that question the reality of man-made global warming have surged in public attention, leading new readers to websites such as Wattsupwiththat.com (run by weatherman Anthony Watts) and climatedepot.com (run by conservative activist Marc Morano). The sites' rising popularity, and the growing influence they appear to wield in shaping public debate, is deeply worrying to the scientific community.

"There has been a transition in the way people get their news over the last decade or so, from the traditional print media to online sources of news," says Michael Mann, one of the key researchers behind the now-famous "hockey stick" graph (which shows the temperature of the Earth steeply rising in the 20th century after a long period of stability - data hotly disputed by the online skeptics, although accepted by the scientific community).

"I think the climate-change-denial movement has recognized that transition was taking place and has really invested a lot of effort and resources in creating this huge infrastructure of online disinformation. And I think it is a challenge for legitimate news organizations to compete with that massive disinformation network."

Mr. Mooney thinks the belief in the reality of man-made global warming, which is the overwhelming consensus in the scientific community, is losing ground in public opinion because of these blogs. "It's a drumming," he laments. "If it's a football game, it would be 56-0."

AN EPIC GAME OF NITPICKING

The major climate-change-skeptic blogs have distinct identities. Mr. Morano's Climate Depot is a ramshackle aggregator site, gathering together news links from around the world, often putting a partisan spin on them. A former producer for the Rush Limbaugh television show and informal adviser to Republican Senator James Inhofe, Mr. Marino has strong ties to the American conservative movement.